Fix mutation
Merge pull request #11 from swtw7466/fix-mutation

突然変異修正
Create Gene module
Gene now holds calculated probs
Discard directions from Gene
Fix tests
Merge pull request #12 from swtw7466/fast-gene

遺伝子は乱択用の計算をあらかじめ行っておく
Haskell-Platform 2013.2
Delete redundant imports